Fig.3.

Filling in of gapped pSJ2 and pSJ3 with Pfu-Pol. The gel shows the starting gapped pSJ2 and pSJ3 (Pfu-Pol−, EcoRI−) and the extended product produced with the addition of Pfu-Pol (Pfu-Pol+, EcoRI−). A subsequent digestion with EcoRI (Pfu-Pol+, EcoRI+) converts the filled plasmid to the linear form, confirming extension by Pfu-Pol, which results in the EcoRI site becoming double-stranded. The size marker is a GeneRuler 1-kb ladder (Fermentas), with the three intense bands being 1, 3, and 6 kb in size, as indicated on the gel.